A. Field of the Invention
The invention generally concerns devices, systems, and methods to predict collisions between an object and a device, part of which is configured to orbit at least partially around the object.
B. Description of Related Art
Medical devices that have a moving gantry, such as a linear accelerator (hereinafter “linac”), are found in the field of radiation therapy, with the therapy source being arranged on the gantry. Such medical devices often have projecting parts (e.g., a treatment head/collimator) that can orbit around a patient in order, for example, to direct the therapy beam onto the patient from different directions. In addition to the movement of the gantry, the patient and couch can also be rotated or laterally moved during treatment. Moving the radiation source and the patient during a treatment can improve radiation dose distributions to a treatment target, as measured by better coverage of the treatment target and the reduced impact on surrounding normal tissue.
However, if one is not careful, these coordinated movements can result in couch-gantry collisions and/or patient-gantry collisions. Undetected potential or actual collisions between the patient/couch and the gantry can be a risk to patient safety, delay the start of the treatment, and reduce clinical efficiency, especially when these collisions are not realized until the treatment plan is finished and the fields are checked on the machine, or even later, when the patient is already on the couch. As such, gantry collisions are a prominent concern for treatment planning when these types of medical devices are used.
Several recent solutions for predicting gantry collisions are software based and use geometric calculations to create a virtual collision detection system. These programs are difficult to implement or can be awkward or cumbersome for routine use in an average clinic.